test: ensure all tests return a useful status code

These tests were all assumed to execute correctly because CTest is not
capable of parsing the TAP output and instead relies entirely on status
codes.

test/backtrace.cpp

@@ -14,5 +14,5 @@ main (int, char **) {
     debug::backtrace ();
     tap.noop ();
 
-    return EXIT_SUCCESS;
+    return tap.status ();
 }

test/bezier.cpp

@@ -249,5 +249,5 @@ main (int, char**)
     test_region<2> (tap);
     test_region<3> (tap);
 
-    return EXIT_SUCCESS;
+    return tap.status ();
 }

test/bitwise.cpp

@@ -61,5 +61,5 @@ main (int, char**)
     test_rotate (tap);
     test_reverse (tap);
 
-    return 0;
+    return tap.status ();
 }

test/colour.cpp

@@ -46,4 +46,6 @@ main (int, char**)
             tap.expect_eq (util::hsv_to_rgb (i.hsv), i.rgb, "hsv-to-rgb %s", i.name);
         }
     }
+
+    return tap.status ();
 }

test/coord.cpp

@@ -17,13 +17,13 @@ main (void)
     static_assert (sizeof (util::point3f) == 3 * sizeof (util::point3f::value_type), "point3f is not packed");
     static_assert (sizeof (util::point4f) == 4 * sizeof (util::point4f::value_type), "point4f is not packed");
 
-    util::TAP::logger t;
+    util::TAP::logger tap;
 
     constexpr util::point2i p { -1,  2 };
 
-    t.expect_eq (-p, util::point2i { 1, -2 }, "unary point negation");
-    t.expect_eq ( p, p, "unary point addition");
-    t.expect (
+    tap.expect_eq (-p, util::point2i { 1, -2 }, "unary point negation");
+    tap.expect_eq ( p, p, "unary point addition");
+    tap.expect (
         std::is_same<
             bool,
             decltype(!p)::value_type
@@ -32,9 +32,9 @@ main (void)
     );
 
     auto vec = util::vector4f (0.5f);
-    t.expect_eq (vec, util::normalised (vec), "normalisation of normalised vector");
+    tap.expect_eq (vec, util::normalised (vec), "normalisation of normalised vector");
 
-    t.expect_eq (sum (util::vector4f::ones ()), 4.f, "elementwise summation");
+    tap.expect_eq (sum (util::vector4f::ones ()), 4.f, "elementwise summation");
 
-    return t.status ();
+    return tap.status ();
 }

test/crypto/arc4.cpp

@@ -388,4 +388,6 @@ main ()
 
         tap.expect (success, "ARC4 %zu", i);
     }
+
+    return tap.status ();
 }

test/fixed.cpp

@@ -47,4 +47,6 @@ main (void)
     test_simple<unsigned,16,16> (tap);
     test_simple<unsigned,26, 6> (tap);
     test_simple<unsigned,32,32> (tap);
+
+    return tap.status ();
 }

test/format.cpp

@@ -211,4 +211,6 @@ main (void)
 
     CHECK_THROW("%c", conversion_error, 1u);
     CHECK_THROW("%c", conversion_error, "foo");
+
+    return tap.status ();
 }

test/geom/aabb.cpp

@@ -48,4 +48,6 @@ main (int, char**)
 
         tap.expect_eq<AABB2f, AABB2f> (small, { { 0.5f, 0.5f }, { 0.5f, 0.5f }}, "unsigned over-contract");
     }
+
+    return tap.status ();
 }

test/hash/checksum.cpp

@@ -51,5 +51,5 @@ main (int, char**) {
             "bsdsum checksum: %s", t.msg);
     }
 
-    return EXIT_SUCCESS;
+    return tap.status ();
 }

test/introspection.cpp

@@ -50,4 +50,6 @@ int main ()
                     util::exactly_equal (d_foo.b, std::get<1> (f_tuple)),
                     "dynamic member access after conversion to tuple");
     }
+
+    return tap.status ();
 }

test/polynomial.cpp

@@ -31,7 +31,7 @@ main (int, char**)
         { "cubic 1 uniq",   {  1, -3,  3, -1 }, { 1, nan, nan } },
     };
 
-    util::TAP::logger test;
+    util::TAP::logger tap;
 
     for (auto &i: CUBICS) {
         std::array<float,3> s = util::polynomial::roots<3> (i.coeffs);
@@ -52,8 +52,8 @@ main (int, char**)
                 ok = false;
         }
 
-        test.expect (ok, "%s", i.name);
+        tap.expect (ok, "%s", i.name);
     }
 
-    return 0;
+    return tap.status ();
 }

test/tuple.cpp

@@ -55,4 +55,6 @@ main ()
 
         tap.expect (std::is_same<dst_t, std::tuple<int>>::value, "tuple type mapping");
     }
+
+    return tap.status ();
 }